(1) Field of the Invention
The present invention relates to a copying machine and, more particularly, to a copying machine having a substantially box-like structure in appearance and employing a slit exposure system.
(2) Description of the Prior Art
A photomechanical copying machine is used for a direct exposure from a given original picture to a printing material (hereinafter referred to as sensitive material) or the exposure of an intermediate photograph for making a printing plate. Copying machines of this kind are classified, on the basis of structural characteristics, into a horizontal-bed type, an overhead type, a vertical type and a box-appearance type.
The last mentioned box-appearance type copying machine is advantageous over the remaining types of the copying machine in that the exposure on the sensitive material is protected against any external light; in that the light for exposure does not leak out of the machine body; and in that the machine can be designed to be compact so that the space for installation of the machine can be much saved.
The exposure system employed in conventional box-appearance type copying machines is a full-size simultaneous exposure system. This full-size simultaneous exposure system, though advantageous in the simplicity of the structure, requires a number of light sources for the exposure. Therefore, if an original picture to be copied is of a large size, the copying machine should inevitably be large-sized, too. As a result, the copying machine for copying a large size picture loses one of the advantages mentioned above, that is, the box-appearance copying machine can be designed to be compact so that the space required for installation thereof can be minimized.